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National Wetlands Research Center

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Invasive Animals

Invasive animals have been recognized as playing a large part in the loss of wetland and coastal habitats. Scientists at the National Wetlands Research Center are investigating several invasive species.

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Asian Carp: Four Asian carp species are now established in the United States (common carp Cyprinus carpio, grass carp Ctenopharyngodon idella, bighead carp Hypophthalmichthys nobilis, and silver carp Hypophthalmichthys molitrix). After introduction, they spread quickly, became abundant, and hurt native fishes either by damaging habitats or by consuming vast amounts of food. Common and grass carps destroy habitat and reduce water quality for native fishes by uprooting or consuming aquatic vegetation. Silver carp commonly jump out of the water and into or over boats, injuring boaters.

Wild boar, Feral hog (Sus scrofa): Wild boar are known by a number of common names: wild hog, feral pig, feral hog, Old World swine, razorback, Eurasian wild boar, and Russian wild boar. They are a growing problem across the Southeastern and Western United States. They can have a significant impact on ground-nesting birds, impact various plant species, increase soil erosion, and can change entire ecological systems. These feral swine are able to harbor and transmit diseases and parasites to both livestock and humans. NWRC researchers, in cooperation with the US Fish and Wildlife Service and the Louisiana Department of Wildlife and Fisheries, are collecting geospatial data to model habitat destruction by feral pigs.

Island applesnail (Pomacea insularum): Exotic applesnails significantly impact wetland plant communities and rice agriculture due to their voracious grazing. They are also a potential vector for disease transmission to humans and animals. The snail tolerates a range of salinities and temperatures and can forage both in and out of water through the use of a gill and lung. Egg masses are laid on solid surfaces (e.g. dock pilings, plants) just above the water line. Once established, they are very difficult to remove.

Nutria (Myocastor coypus): The invasive nutria, or coypu, causes problems in coastal marshes and baldcypress swamps, especially in Louisiana. Introduced from South America for their fur, they now number in the millions because of the fur trade collapse. Nutria feed on the tender roots of plants, seedlings, and saplings, completely stripping vegetation in areas where they are concentrated. The USGS studies worldwide nutria distribution and eradication, maps nutria destruction, and develops computer models to predict damage and simulate management options.

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Page Last Modified: Monday, 28-Sep-2015 14:02:18 EDT